Other Resources

Sometimes also referred to as Boost (as is Elixir which can sometimes cause confusion).

What is it good for?

Gold Dust is used to give a short term (24 hour) increase in a Hero's level. You do this by clicking on a Hero then clicking on the "Boosts" tab on the right. Each use increases the Hero by one level. The cost for the next use though raises substantially each time. The cost resets when the effects of the previous use(s) wears off.

Where do you get it?

It is sometimes availlable in the main Shop as part of a package; is often available to purchase in the other shops (Dark Shop, Journey Shop, etc); can be received as a Brawl reward; can be won in Turf Wars; may be received as a quest reward, or can be a Twitch drop reward. Lastly you can Sacrifice Hero Souls which will burn Hero Souls in exchange for Gold Dust. The more rare the card, the less cards need to be burned to gain dust.

Journey Keys have two functions. Their most common use is to allow you to have fights in the Journey area. Winning these fights win you Ancient Coins for use in the Journey Shop, some Hero Souls of the Hero you defeated, and a few gems for the first time you defeat any Hero in the Journey area (awarded in the Quest area).

Their second potential use is only found during Events. Many events have as part of them, fights against Heroes which is one of the main ways to get those Heroes. Winning the fights gives you their Hero Souls (making them available to you) and Event Resources (see above).

Where do you get them?

You receive one Key every 6 hours up to a maximum of 5 keys (shown below the Blimp). They can also be won in Brawls and are sometimes given as a reward to those who attend Panoramik's Mighty Party Twitch broadcasts. Join Panoramik on the Discord chat program to see announcements for those and ask questions of the devs and other users.